I've definitely had mixed experiences with Tilly - ordered a custom with her last year and it is by far the best custom I've ever ordered, it was exactly what I wanted, she's a great director. But on the other hand, she's absolutely awful at responding - it actually took me over a year to reach her via email in order to even enquire about the custom.
She's been difficult to get hold of ever since, but as been mentioned, she's very active on Twitter, as well as when sending out group which I find rather frustrating.